With an ever-growing demand for higher capacity and lower cost of batteries in electric vehicles and portable electronics, lithium-sulfur (Li—S) batteries represent a promising alternative to the currently prevalent lithium-ion batteries. Li—S batteries offer a theoretical specific capacity of 1675 mAh/g and an energy density of 2600 Wh/kg, nearly ten times the theoretical specific capacity and five times the energy density of the current state-of-the-art lithium-ion batteries. However, Li—S batteries suffer from polysulfide shuttling, which is caused by the much faster migration of soluble lithium polysulfide species (Li2Sn, 4≤n≤8) to Li anode compared to the slower redox interconversions between these soluble lithium polysulfide species and insoluble species (elemental Sg, Li2S2, Li2S) in the cathode. Traditionally, to counter this undesired effect, the Li2Sn species needed to be confined inside the cathode. Other strategies, e.g. the use of concentrated electrolytes to lower solubility of Li2Sn, and Li anode protection against shuttled Li2Sn have been suggested. However, even with these recent advances, the performance of Li—S batteries remains limited by insufficient control of polysulfide shuttling.
To overcome these limitations, electrocatalysis can be used to accelerate the interconversions between the soluble and insoluble sulfur species, thereby hampering polysulfide shuttling. Electrocatalytic systems based on nanostructured Pt and Ni, MS2 (M=Ti, V, Co, Mo, W), TiN, and a perylene bisimide-Li2Sn gel network coupled with graphene nanosheets and/or nanoscale porous carbons, have been reported. The complexity of these multicomponent systems makes it difficult to probe their chemistry at a molecular level, impeding rational development of affordable yet efficient electrocatalysts. There is an ongoing need for Li—S batteries with reduced polysulfide shuttling. The cathodes and Li—S batteries described herein address this need.